# Equivalence class testing

Equivalence Class Testing, which is also known as Equivalence Class Partitioning (ECP) and Equivalence Partitioning, is an important software testing technique used by the team of testers for grouping and partitioning of the test input data, which is then used for the purpose of testing the software product into a …Jul 23, 2019

## How to determine the equivalence classes?

Properties of Equivalence Classes

• Every element a ∈ A is a member of the equivalence class [ a]. ∀ a ∈ A, a ∈ [ a]
• Two elements a, b ∈ A are equivalent if and only if they belong to the same equivalence class. …
• Every two equivalence classes [ a] and [ b] are either equal or disjoint. …

## What are equivalence classes?

The word “class” in the term “equivalence class” may generally be considered as a synonym of “set”, although some equivalence classes are not sets but proper classes. For example, “being isomorphic ” is an equivalence relation on groups, and the equivalence classes, called isomorphism classes, are not sets. ). The surjective map

## What is an equivalent class?

Equivalence Class. An equivalence class is defined as a subset of the form, where is an element of and the notation “” is used to mean that there is an equivalence relation between and .It can be shown that any two equivalence classes are either equal or disjoint, hence the collection of equivalence classes forms a partition of .

## How many equivalence classes in the equivalence relation?

How many equivalence classes are there for the congruence relation? We know that each integer has an equivalence class for the equivalence relation of congruence modulo 3. But as we have seen, there are really only three distinct equivalence classes. Using the notation from the definition, they are: = {a ∈ Z | a ≡ 0 (mod 3)},

## What is meant by equivalence class?

An equivalence class is the name that we give to the subset of S which includes all elements that are equivalent to each other. “Equivalent” is dependent on a specified relationship, called an equivalence relation. If there’s an equivalence relation between any two elements, they’re called equivalent.

## How do you identify classes in equivalence class testing?

Equivalence classes are identified by selecting each input condition (usually the phrase or sentence in the specification) and by dividing it into two or more groups.

## What is equivalence partition in black-box testing?

Equivalence partitioning is a black-box testing method that divides the input domain of a program into classes of data from which test cases can be derived. Test case design for equivalence partitioning is based on an evaluation of equivalence classes for an input condition.

## What is the difference between BVA and ECP?

BVA technique reduces Test Coverage and picks data on the boundary of various regions/classes of ECP. We can choose Data on the boundaries of classes. It is a subset of ECP. While ECP divides data into Two regions, these regions can increase & decrease according to data.

## Why would a tester use equivalence class testing?

Equivalence class testing helps reduce the number of test cases, without compromising the test coverage. Reduces the overall test execution time as it minimizes the set of test data. It can be applied to all levels of testing, such as unit testing, integration testing, system testing, etc.

## How do you perform an equivalence test?

A very simple equivalence testing approach is the “two one-sided tests” (TOST) procedure (Schuirmann, 1987). In the TOST procedure, an upper (ΔU) and lower (−ΔL) equivalence bound is specified based on the smallest effect size of interest (SESOI; e.g., a positive or negative difference of d = . 3).

## What is equivalence testing in software?

Equivalence partitioning or equivalence class partitioning (ECP) is a software testing technique that divides the input data of a software unit into partitions of equivalent data from which test cases can be derived. In principle, test cases are designed to cover each partition at least once.

## What is sanity testing?

Definition: Sanity testing is a subset of regression testing. After receiving the software build, sanity testing is performed to ensure that the code changes introduced are working as expected . This testing is a checkpoint to determine if testing for the build can proceed or not.

## What is the difference between equivalence partitioning and boundary testing?

In Equivalence Partitioning, first, you divide a set of test condition into a partition that can be considered. In Boundary Value Analysis you then test boundaries between equivalence partitions. Appropriate for calculation-intensive applications with variables that represent physical quantities.

## What is BVA in testing with example?

Boundary Value Analysis (BVA) is a Black-Box testing technique used to check the errors at the boundaries of an input domain. The name comes from the Boundary, which means the limits of an area. So, BVA mainly focuses on testing both valid and invalid input parameters for a given range of a software component.

## What is BVA and Equivalence Partitioning?

Boundary value analysis is testing at the boundaries between partitions. Equivalent Class Partitioning allows you to divide set of test condition into a partition which should be considered the same.

## How are BVA values determined?

Test Case Design for BVA: While designing the test cases for BVA first we determine the number of input variables in the problem. For each input variable, we then determine the range of values it can take. Then we determine the extreme values and nominal value for each input variable.

## What are equivalence classes in Java?

Equivalance Partitioning – It is a technique where tester divide the test conditions into groups and sets. System should handle them equivalently hence called equivalence classes. To test one condition from each partition will work to assume all condition will work in that partition.

## What is class testing and its uses?

Class testing is the base of object-oriented software testing. It involves three aspects: testing each method, testing the relations among class methods and testing the inheriting relation between class and subclass.

## How many test cases are there in worst case testing if there are 4 variables in a module?

Test cases: A= Number of testing points. These testing points are min, min+, nominal, max- and max. We can generate 25 test cases from both variables x1 and x2 by making a combination of each value of one variable with each value of another variable.

## What is the importance of equivalence class testing?

Among the various software testing techniques performed by the team of testers, there is one important technique- Equivalence Class Testing -that assists the team in getting accurate and expected results, within the limited period of time and while covering large input scenarios.Since , it plays such a significant role in Software Testing Life Cycle (STLC), following is a comprehensive discussion on Equivalence Class Testing and its various important components.

## How to ensure accuracy and precision of equivalence class testing?

To ensure the accuracy and precision of equivalence class testing, define the input data in terms of intervals and sets of discrete values.

## What is ECP testing?

Equivalence Class Testing, which is also known as Equivalence Class Partitioning (ECP) and Equivalence Partitioning, is an important software testing technique used by the team of testers for grouping and partitioning of the test input data, which is then used for the purpose of testing the software product into a number of different classes.

## What is a test case based on?

Thereafter, the test cases are designed and created based on each class attribute (s) and one element or input is used from each class for the test execution to validate the software functioning, and simultaneously validates the similar working of the software product for all the other inputs present in their respective classes.

## Why is equivalence class important?

Equivalence class testing helps reduce the number of test cases, without compromising the test coverage.

## How many valid and invalid inputs are needed for a team?

The team needs to select one valid and one invalid input value each, if the input conditions are broken or not stated accurately.

## How many classes are there in 1500 inputs?

Now, as per the requirement specifications, these inputs are grouped together to form some classes. Now, instead of testing 1500 inputs, we have formed 4 classes and are accordingly dividing the inputs into a category of valid and invalid inputs, which reduces the work of the test case preparation.

## What is equivalence class testing?

Equivalence class testing (Equivalence class Partitioning) is a black-box testing technique used in software testing as a major step in the Software development life cycle (SDLC). This testing technique is better than many of the testing techniques like boundary value analysis, worst case testing, robust case testing and many more in terms of time consumption and terms of precision of the test cases. Since testing is done to identify possible risks, equivalence class testing performs better than the other techniques as the test cases generated using it are logically identified with partitions in between to create different input and output classes. This can be shown from the next-date problem which is stated below:

## Which type of partitioning generates more efficient test cases that should be considered during risk assessment?

Hence the above example proves that equivalence partitioning generates more efficient test cases that should be considered during risk assessment.

## What is equivalence class testing?

The equivalence class testing significantly simplifies and accelerates the system function checking. Instead of creating a great number of test cases for each input data combination, it needs to fulfil only one test case. As the practice shows, the result will be valid for all values of this equivalence class.

## What happens if a bug is detected with the help of one test case from the certain equivalent class?

If the bug is detected with the help of one test case from the certain equivalent class, then the input of the rest of incoming data variants will throw the same error.

## How to identify equivalence class?

Identification of Equivalence Classes 1 Cover all test data types for positive and negative test scenarios. We have to create test data classes in such a way that covers all sets of test scenarios but at the same time, there should not be any kind of redundancy. 2 If there is a possibility that the test data in a particular class can be treated differently then it is better to split that equivalence class.#N#For example, in the above example, the application doesn’t work with numbers – less than 10. So, instead of creating 1 class for numbers less than 10, we created two classes – numbers 0-9 and negative numbers. This is because there is a possibility that the application may handle negative numbers differently.

## What is the whole success of equivalence class testing?

The whole success of equivalence class testing relies on the identification of equivalence classes. The identification of these classes relies on the ability of the testers who creates these classes and the test cases based on them.

## What happens if you incorrectly identify equivalence classes?

Incorrectly identified equivalence classes can lead to lesser test coverage and the possibility of defect leakage.

## Why do we create a different class for negative numbers?

Since negative numbers can be treated in a different way so, we will create a different class for negative numbers in order to check the robustness of the application.

## Can special characters have equivalence?

Just like the equivalence class for alphabets, we can have a separate equivalence class for special characters.

## Can we pass a test data from a particular equivalence class to an application?

So, instead of testing all the combinations of input test data, we can pick and pass any of the test data from a particular equivalence class to the application and assume that the application will behave in the same way for the other test data of that class. Let’s understand this with the help of an example.

## How to determine equivalence class?

1. Identifying the domain: Identify the domain for every input parameter. With this technique, at lease one valid and one invalid equivalence class per parameter has been derived exclusively from the interface specification.#N#2. Refine the equivalence classes based on the specification: In order to further subdivide equivalence classes, information about the functionality of method is needed.#N#3. Select Representative: To get input data, one representative value must be chosen for every equivalence class. According to equivalence class theory, any value of an equivalence class can be used.#N#4. Combine the test cases: Combine the values to test cases.

## What is an equivalence class?

The equivalence class is a set of data values that the tester assumes are processed in the same way by the test object. Besides equivalence classes for correct input, those for incorrect input values must be tested as well.

## How many equivalence classes are there in a test?

The equivalence class technique results in at least 2 equivalence classes (one valid and one invalid) for each of these parameters of the test object. In order to specify a test case, we must assign each parameter an input value.

## What is equivalent partitioning?

Equivalence partitioning (also called Equivalence Class Partitioning or ECP) is a software testing technique that divides the input data of a software unit into partitions of equivalent data from which test cases can be derived.

## How to complete test cases?

To complete the test cases, the tester must define the preconditions and the expected result for every test case. The same principle of dividing into equivalence classes can be used for the output data. Partitioning into equivalence classes and selecting the representatives should be done carefully. The probability of failure detection is highly dependent upon the quality of the partitioning as well as which test case are executed.

## What is the best test value?

The best test values are certainly those verifying the boundaries of equivalence classes. The equivalence class for incorrect values is derived from the following consideration that incorrect values are numbers that are greater or smaller than the range of the applicable interval or every non-numeric value. Zero is also an input, which often leads to failure.

## How many times should a test case cover each partition?

In principle, test cases are designed to cover each partition at least once.

## How many valid and invalid equivalence classes are defined?

If a specific value is given as input, then one valid and two invalid equivalence classes are defined.

## What is equivalence portioning?

In equivalence portioning, equivalence classes are evaluated for given input conditions. Whenever any input is given, then type of input condition is checked, then for this input conditions, Equivalence class represents or describes set of valid or invalid states.

## What percentage is considered invalid?

If percentage entered is between 50 to 90 %, then equivalence partitioning method will show valid percentage.

## What is the ECP method?

It is a software testing technique or black-box testing that divides input domain into classes of data, and with the help of these classes of data, test cases can be derived. An ideal test case identifies class of error that might require many arbitrary test cases to be executed before general error is observed.

## What is equivalence partition?

The equivalence partitions are usually derived from the requirements specification for input attributes that influence the processing of the test object.

## What is the boundary value of a test vector?

The values of the test vector at the strict condition of the equality that is INT_MIN = x + y and INT_MAX = x + y are called the boundary values, Boundary-value analysis has detailed information about it. Note that the graph only covers the overflow case, first quadrant for X and Y positive values.

## What is ECP in testing?

Equivalence partitioning or equivalence class partitioning ( ECP) is a software testing technique that divides the input data of a software unit into partitions of equivalent data from which test cases can be derived. In principle, test cases are designed to cover each partition at least once. This technique tries to define test cases that uncover classes of errors, thereby reducing the total number of test cases that must be developed. An advantage of this approach is reduction in the time required for testing software due to lesser number of test cases.

## What is blanket test coverage?

Blanket test coverage can reveal bugs that would not be caught using the equivalence partitioning method, if the software includes sub-partitions which are unknown to the tester. Also, in simplistic cases, the benefit of reducing the number of test values by using equivalence partitioning is diminished, in comparison to cases involving larger ranges (Example: 0-1000, 1001-2000, 2001-3000).

## Why is it necessary to select one test case out of each partition?

In other words, it is sufficient to select one test case out of each partition to check the behaviour of the program. To use more or even all test cases of a partition will not find new faults in the program. The values within one partition are considered to be “equivalent”. Thus the number of test cases can be reduced considerably.

## Can an inexperienced tester use 1 to 12 as a test case?

An inexperienced tester may be tempted to use as test cases the input data 1 to 12 for the month and forget to select some out of the invalid partitions. This would lead to a huge number of unnecessary test cases on the one hand, and a lack of test cases for the dirty ranges on the other hand.

## Is equivalence partitioning a stand alone method?

Equivalence partitioning is not a stand-alone method to determine test cases. It has to be supplemented by boundary value analysis. Having determined the partitions of possible inputs the method of boundary value analysis has to be applied to select the most effective test cases out of these partitions.

## Types of Equivalence Class Testing

• The equivalence class testing is divided into four different types that forms an integral part of testing mechanisms and perform action based on different data sets. They are as follows: 1. Weak Normal Testing Class: This type of testing uses only a single variable from each equivalen…

## Why Do We Need Equivalence Class Testing?

• It is the best practice for testing purpose than Boundary value analysis that is a formation of stress and negative testing. So we require and mainly use equivalence class testing approach for the below features: 1. It uses the black box testing approach that refrain the testers to test and analyze the software product externally. 2. The equivalence class testing, is also known as equiv…

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## Importance of Equivalence Class Testing

• It is one of the powerful testing process in entire software testing approach that helps in reducing the redundancy in testing methods and making the process agile. It is one of the testing techniques that provides an indefinite amount of benefits to the testing team and ensures better quality software products to be delivered to the clients. The list of its usefulness are as follows: …

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## Conclusion

• Equivalence class testing that is purely a specification based testing is the popular and best method for testing purposes that decreases test cases required to develop a software product. This testing approach is famous worldwide for its greater test coverage and minimizing time. This is a guide to Equivalence Class Testing. Here we discuss the introduction, types, why do we nee…

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